1. Field of the Invention
This invention relates generally to tires and wheels for vehicles and in particular to tires and wheels for creating the appearance of low-profile tires mounted on large-diameter wheels.
2. Description of the Related Art
In recent years, consumer demand for large-diameter vehicle wheels mounted within low-profile tires has increased dramatically. Such wheels and tires create a stylish look for the vehicle on which they are used, but they cost much more than standard-sized wheels and tires. As a consequence, large-diameter wheels and low profile tires are desired by many consumers, but are beyond the financial reach of a large segment of the market. Moreover, most companies that make wheels are set up for mass production of wheels of certain standard sizes, and have often lagged behind consumer demand in developing or re-tooling expensive equipment, including molds and casting machinery, to produce the largest wheels desired by consumers.
In addition, as wheels become larger and the corresponding tires become smaller, the ride performance of the wheel-tire combination often suffers. For example, a smaller tire surrounding a larger wheel provides less air volume to support the vehicle. The proper amount of air volume allows the vehicle to absorb substantial vibration and other vertical and/or horizontal motion in the wheels. When the air volume is reduced, the vehicle may not ride as smoothly and the weigh-load rating may be more limited. By limiting the weigh-load rating, the market for certain types of vehicles (such as trucks or SUVs) may be significantly decreased. Thus, it would be advantageous to provide the appearance of thinner tire and larger wheel while providing a smoother ride, higher weight-load rating, and more tire between the wheel and the road.
Some consumers who want the look of large-diameter wheels, but who cannot afford them or are concerned with diminished ride performance, may be willing to pay an intermediate cost to make standard-sized wheels and tires take on the appearance of the more expensive (and possibly unavailable) products. Detachable wheel extensions, such as the one shown in U.S. Patent Publication No. US 2002/0079735 A1, have been used to attempt to simulate the appearance of larger wheels mounted within low-profile tires. However, such extensions mask a portion of the front face of the wheel and do not provide a surface integral with the design on the face of the wheel. Thus, the attempted simulation does not have a realistic appearance.
In particular, some wheel extensions of the prior art have an inner ring that is removably secured within an inside edge of the outer lip of the existing wheel using a compression fit (as with a standard hub cap). A wide outer flange is attached to the inner ring and extends radially outwardly across a portion of the outside tire wall. The wheel extensions are intended to be used with many different types of wheels having a variety of surface designs on their front faces. The outward surfaces of the inner ring and outer flange generally have a smooth, generic appearance to attempt to aesthetically interface with all of these different designs. Although outer flanges of the prior art may include a narrow, upturned lip formed along the outer diameter of the flange and/or an undulated outward surface (e.g., a smooth stair-step pattern of concentric rings), the flanges do not include protrusions, indentations, or slits on their surfaces as are commonly found on the central portion of the front face of many wheels.
The inner ring for securing the wheel extension to the wheel is generally at least about ½ inch thick around its circumference, which covers up a significant portion of the underlying wheel face. When mounted on a wheel with a 17-inch diameter, a ½-inch thick ring makes the wheel appear to be only 16-inches in diameter. This results in a reduction of the visible surface area of the wheel by well over 10 percent. In addition, the smooth outward surfaces of the inner ring and outer flange generally do not blend in well with the existing design of the wheel. Indeed, the wheel extensions of the prior art are usually easily detectable by even a casual observer, and merely give the appearance of an over-extended add-on lip covering a portion of the outer tire wall. Thus, the attempted simulation is not only ineffective, it actually creates the opposite effect. Rather than simulating a larger wheel mounted within a low profile tire, the wheel extension gives the appearance of a smaller wheel mounted on a standard tire.